Following the propagation of a composite resin as a dental restorative material, it is required to undergo firm adhesion with safe and confidence between a tooth structure and the composite resin by a simple handling. As adhesion methods which have hitherto been employed, after an acid etching by phosphoric acid or citric acid and so on, a series of handling of water washing.fwdarw.drying.fwdarw.application of a primer.fwdarw.drying .fwdarw.application of an adhesive.fwdarw.polymerization.fwdarw.filling of a composite resin can be exemplified as a representative adhesion method of a restoration. In actual restoration, it is the present state that it takes time to accomplish such handling and that no adhesion with confidence is attained.
Thus, in recent years, adhesion methods for simplifying such complicated handling steps have been being investigated. For example, a new type primer is proposed in, JP-A-3-240,712 and JP-A-7-82,115. In the proposed methods using the new type primer, a tooth is treated with a self-etching primer by which it is said that an etching and a priming can be carried out simultaneously, and after drying, a bonding agent is applied. In other words, a surface of the tooth having a cavity formed therein is treated with the self-etching primer, and the self-etching primer penetrates into the tooth structure while dissolving a smear layer generated upon the cavity formation. Then, a bonding agent is applied, whereby the self-etching primer and the bonding agent are integrated and set to obtain a firm adhesive layer.
However, such kinds of self-etching primers which are commercially available at present need a polymerization catalyst and a polymerization accelerator for setting the polymerizable component in the self-etching primer, and in order to obtain a self-etching primer having good storage stability and stable adhesive capacity, the polymerization catalyst must be separated from the polymerization accelerator. For this reason, self-etching primers which are commercially available at present are constructed by a two-pack type self-etching primer of a polymerization catalyst and a poly-merization accelerator, and the two packs must be mixed with each other before the use. Accordingly, it is not always said that its handling is easy, and there may be a possibility that unstable adhesion is obtained due to a metering error.